<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			/* 向选定的元素后插入内容 */
			p:after{
				content:"，hello！ ";
			}
		</style>
	</head>
	<body>
		<p>我是p标签</p>
	</body>
</html>
